Question

有没有办法将属性值从基类的对象复制到派生类的对象？

class Base():
    def __init__(self):
       self.a = 10
       self.b = None

class Derived(Base):
       self.c = 30

def main():
    base = Base()
    base.b = 20
    derived = Derived(base)

我试图找到一种更复杂的pythonic来复制基类对象的值，因为基类有很多变量，但是我找不到一个简洁的方法。

我想要变量＆＃34;派生＆＃34;得到它的价值＆＃34; a = 10 b = 20 c = 30＆＃34;。

Answer 1

不如何进行继承。您将基类的实例传递给派生类的__init__，这与继承其属性完全无关。相反，做：

class Base():

    def __init__(self):
       self.a = 10


class Derived(Base):

    def __init__(self):
       super(Derived, self).__init__()  # calls Base.__init__
       self.b = 'abc'


def main():
    base = Base()
    derived = Derived()

Answer 2

如何使用默认参数？

class Base():
    def __init__(self, a=10):
       self.a = a
class Derived(Base):
    def __init__(self, a=10, b=None):
       super().__init__(a)  # python 3
       # Base.__init__(self, a)  # python 2
       self.b = b or 'abc'

def main():
    base = Base()
    derived = Derived()

    print(base.a)
    print(derived.a, derived.b)

main()

# output:
# 10
# 10 abc

还要注意你如何调用＆＃39;构造函数＆＃39;负责设置__init__。

的基类self.a

在Python中复制基类对象的值

2 个答案: